If you use the LA only, you will NOT have the D12 HD, as those HD would be added to the ECL. If the HD is houseruled as not counting towards ECL, well... you'd be massively stronger than everyone else, most probably. I'd also likely want to play with a different concept if Telos ends up proving ineffective in the adventure, since I'm sure I could come up with interesting ideas with RHD+LA characters, particularly when only their LA counts toward ECL.